The invention relates generally to thermionic power conversion systems, and more particularly to an integrated modular thermionic system for operation aboard orbiting spacecraft or in other remote environments in providing large amounts of power in short pulses.
In the operation of a thermionic converter, heat energy is converted directly to electrical current by heating a metallic emitter to sufficiently high temperatures that electrons escape the emitter and flow to a cooler collector. The source of heat energy for conversion to electrical current may be any of several types, an exothermic chemical reaction system being one such efficient type. In order to promote efficient operation of a thermionic system in the generation of useful amounts of electrical power, especially in such a system utilizing a chemical reaction, the system must not only generate large amounts of heat required for energizing the thermionic components, but must also provide for rejection of waste heat from the cold side of the thermionics.
The present invention provides an improved chemical reaction fueled thermionic power conversion system which is modular in structure for application aboard earth orbiting spacecraft or in other remote mission environments. The system is substantially closed and includes in compact modular form a centrally located heat source comprising a pair of chemical reactants which react exothermally, e.g., the lithium and sulphur hexafluoride system; an annular thermionic converter system is disposed concentrically around the heat source, the heat source/converter assembly being surrounded by an unconventional heat rejection system for removing heat from the cold side of the thermionics and thereby promoting efficient operation of the system. Preferred reactants occupy less total space after reaction than in an unreacted state so that the reaction proceeds within a closed system without generation of effluents or substantial overpressure. The system has essentially no moving parts which obviates friction and vibration problems. Each subsystem of the invention may have a modular configuration which facilitates refueling and replacement of components.
The power system of the invention has substantial utility as a power supply for directed or kinetic energy weapons, or other application requiring large amounts of power in short pulses.
It is therefore a principal object of the invention to provide an integrated high power modular thermionic power system.
It is a further object of the invention to provide a high power thermionic system for pulsed operation.
It is a further object of the invention to provide a closed thermionic power system having an easily replenishable heat source.
These and other objects of the invention will become apparent as the detailed description of representative embodiments proceeds.